[animeshz]

I really like the yahoo mobile interface, for one it lists all the subscriptions and unsubscribe button at one panel, second its search is really powerful and can pick all the matching mails from certain sender, or having some word occurring (unlike Gmail, in its mobile you can't select all, and in desktop everything is paginated).

It also lists all transactions mail in one panel, so you can clear them at once if everything is checked, you can however use gmail to filter down the promotional and spam emails and clear them at once from desktop.

I initially thought of using python or something with SMTP, but it wasn't that feasible than how much mobile yahoo client helped me. I trimmed down 6 mailbox with over 20k mails each (one of them going over 43k), to around 40 mails on each.